In a battery pack for electric vehicles, a battery module constructed by a battery cell assembly, a junction box for performing supply, interception, and distribution of heavy-electric current by means of a relay circuit, and a battery controller for battery management are mounted in the internal space of a battery pack case. In such a battery pack, a battery pack structure, in which a battery module, a junction box, and a battery controller are connected to each other by means of a heavy-electric harness constructed by heavy-electric wires tied together and a weak-electric harness constructed by weak-electric wires tied together, is well known. One such battery pack structure has been disclosed in Patent document 1.
However, in the battery pack structure disclosed in Patent document 1, the internal space of the battery pack case is classified into three-split rectangular regions, and three battery modules are mounted on the respective rectangular regions. Also, a T-shaped clearance space, defined among sidewalls of the three battery modules, opposed to each other, is used as a junction-box mounting space and also used as a harness wiring path. Therefore, when connecting the junction box and the battery controller, mounted apart from each other, to each other via a harness, harness-wiring that the harness has to be bent along the bent clearance path is required. This leads to the problem, such as the deteriorated workability of the harness wiring and the lowered durability of the harness.
On the other hand, the clearances, ensured when the plurality of battery modules have been mounted in the internal space of the battery pack case, are also used as temperature-adjustment air passages through which temperature-adjusting air for battery-temperature management flows. In this manner, the clearances, ensured when the plurality of battery modules have been mounted, serve as the temperature-adjustment air passages and also serve as the harness wiring paths. Hence, the bent harness, which may disturb the temperature-adjusting air flow, has to be wired in the clearances through which the temperature-adjusting air flows. As a result of this, there is a problem that such a bent harness acts as passage resistance and thus smooth flow of temperature-adjusting air cannot be ensured.